KANGFUPEN Liquid Dressing for Chronic Radiation-Induced Rectal Injury

Baseline Assessments

All enrolled patients must complete the following evaluations:

• Medical history including primary tumor type, histopathology, staging and radiotherapy details (timing, technique, and total dose)
• Physical examination
• ECOG performance status
• Laboratory tests including complete blood count, stool occult blood, liver/kidney function and tumor markers
• Pelvic scans to exclude tumor recurrence/progression
• Full colonoscopy with photographic documentation. Images every 5cm from anus to splenic flexure, and at sites of severe mucosal reaction additionally
• Grading based on LENT-SOMA, RTOG, and CTCAE v5.0 criteria

Treatment protocol Kangfupen (liquid dressing) retention enema

• Dosage: 50 mL once daily for 3-6 months
• Administration depth: Determined by colonoscopy findings Enema preparation & administration 1. Reconstitution:

• Transfer liquid from plastic to brown glass vial
• Shake vigorously to dissolve lyophilized powder
• Return solution to plastic bottle and shake again 2. Delivery:

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• Position: Left lateral decubitus with waste basin
• Slowly instill 50 mL into rectum
• Retain for ≥30 minutes, rotating positions every 15 minutes (left/right lateral, supine, knee-chest)

Concomitant therapies Permitted: probiotics, smectite, antibiotics, stool softeners Prohibited: 5-ASA drugs (mesalazine/sulfasalazine), endoscopic hemostasis (e.g., argon plasma coagulation), formaldehyde/HBO/surgery/fecal microbiota transplant, other enema therapies.

Toxicity monitoring Potential adverse events include allergic reactions and mechanical injury (bleeding/perforation). Required Actions include immediately discontinuing treatment and reporting to the principal investigating site within 24 hours.

All adverse events will be assessed using CTCAE v5.0 criteria.

Follow-up schedule Month 1-2: LENT-SOMA, RTOG/CTCAE grades, IBDQ, symptom improvement evaluation Month 3: Above + sigmoidoscopy with Vienna scoring Every 6 months after month 6: sigmoidoscopy + all scales + physician's global assessment of treatment efficacy

Inclusion criteria

• Fully voluntary with decision-making capacity
• 18-80 years old
• Completed pelvic radiotherapy for malignancy ≥3 months prior
• Evidence of chronic radiation-induced rectal injury (RTOG Grade ≥2)
• Evidence of radiation-induced rectal injury on colonoscopy (within 3 months, Vienna endoscopic score ≥1)
• No prior surgery
• ECOG score 0-2
• Estimated survival ≥1 year

Exclusion criteria

• Primary rectal tumours or pelvic malignancies with rectal involvement
• Uncontrolled, recurrent, or metastatic tumours
• Concurrent anticancer therapies including radiotherapy, chemotherapy, targeted therapy, immunotherapy and traditional Chinese medicine with anti-tumour properties
• Patients with intestinal fistula, perforation, or obstruction
• History of electrocautery treatment within 1 month
• Recent medication use (within 2 weeks): traditional Chinese medicine enemas, mesalazine (oral or rectal) and other anti-inflammatory bowel medications
• History of superoxide dismutase allergy
• Pre-existing chronic colitis, ulcerative colitis, or nonspecific proctitis
• Connective tissue diseases requiring long-term corticosteroid therapy
• Pregnant or lactating women
• Active infection or fever
• Other severe comorbidities potentially affecting trial compliance: unstable cardiac disease requiring treatment, renal disorders, chronic hepatitis, poorly controlled diabetes and psychiatric illnesses